/*
 * Copyright (c) 2018-2020 "Graph Foundation,"
 * Graph Foundation, Inc. [https://graphfoundation.org]
 *
 * This file is part of ONgDB.
 *
 * ONgDB is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
/*
 * Copyright (c) 2002-2020 "Neo4j,"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.shell;

import java.io.Serializable;

/**
 * Represents a shell client which communicates with a {@link ShellServer}.
 * A client is very thin, it just grabs a command line from the user and sends
 * it to the server, letting everything happen server-side.
 */
public interface ShellClient
{
    Serializable getId();

    /**
     * Grabs the console prompt.
     */
    void grabPrompt();

    /**
     * Evaluates a line and reacts to it.
     * @param line the line to evaluate.
     * @throws ShellException if something went wrong.
     */
    void evaluate( String line ) throws ShellException;

    /**
     * Evaluates a line and reacts to it.
     * @param line the line to evaluate.
     * @param out output just for this evaluation.
     * @throws ShellException if something went wrong.
     */
    void evaluate( String line, Output out ) throws ShellException;

    /**
     * Tells the client session to end, i.e. exit the {@link #grabPrompt()}.
     */
    void end();

    /**
     * @return the server to communicate with.
     */
    ShellServer getServer();

    /**
     * @return the output instance where output will be passed to.
     */
    Output getOutput();

    /**
     * @return the current prompt.
     */
    String getPrompt();

    /**
     * @return the time (millis) when the most recent connection was made
     * to the master.
     */
    long timeForMostRecentConnection();

    /**
     * Shuts down any resource needing to shut down.
     */
    void shutdown();

    void setSessionVariable( String key, Serializable value ) throws ShellException;
}
